A conventional door lock set includes: an outer lock held on an outer trim plate retained on an outside surface of a door, a locking bolt slidably held in a central portion of the lock set for locking a door on a door frame upon locking of the outer lock, an inner knob or handle rotatably or pivotally formed on an inner trim plate retained on an inside surface of the door, having a spindle axially linked between the outer lock and the inner knob.
However, the conventional door lock set can be easily damaged or destroyed intentionally by an intruder. Meanwhile, when assembling the three major parts of the conventional door lock set, namely (a) the outer trim plate having outer lock held thereon, (b) the inner trim plate having inner knob formed thereon, and (c) the locking bolt perpendicularly connected to the spindle, as directed from three directions including an outside surface of the door (first direction), an inside surface of the door (second direction) and the end surface facing the door frame (third direction), it may cause difficulty for assembling these parts from three directions and also requiring skill for stably positioning or supporting the parts whenever assembling the lock set.
The present inventor has found the drawbacks of the conventional door lock set and invented the present door lock set as interiorly reinforced.
The object of the present invention is to provide a door lock set including: an outer lock held in an outer trim plate positioned on an outside surface of a door, a latch device retained in the door for protruding a latch for locking the door on a door frame, an inner reinforced retaining member fastened with the outer lock and retained on an inside surface of the door, an outer reinforced retaining member fastened with the inner reinforced retaining member across the thickness of the door, an inner trim plate having an inner knob or handle rotatably or pivotally held on the inner trim plate fastened to the inner reinforced retaining member and retained on an inside surface of the door; with the inner knob coaxially linked with the outer lock by a spindle connected with the latch device for operatively protruding the latch for locking the door; and the outer lock fastened to the inner reinforced retaining member for retaining the outer trim plate on the outside surface of the door, thereby providing a door lock set easily assembled but difficultly damaged.